<?php
header('Content-type:text/html;charset=utf-8');
$name='小明';
$score=78;
if(is_int($score)||is_float($score)){
    if($score>=90 && $score<=100)  {
        $str ='A级';
    }elseif ($score>=70 &&  $score<=90){
        $str='B级';
    }elseif ($score>=60 && $score<=70){
        $str='C级';
    }elseif ($score>=50 && $score<=60){
        $str='D级';
    }elseif ($score>=0 && $score<=60){
        $str='E级';
    }else {
        $str = '学生成绩必须在0~100！';
    }
}else{
    $str='输入的学生成绩不是数值!';
}
echo "<h2>学生成绩等级</h2><p>学生姓名:".$name."<p>学生分数:".$score."分<p>成绩等级：".$str;
?>
